“Current singularities” observed on Astrid-2 Original Research Article

Swedish microsatellite Astrid-2 carried out electric and magnetic field measurements at 1000 km altitude during its operation in January–July, 1999. At a number of occasions sharp gradients in the magnetic field were observed by the satellite. If interpreted as spatial gradients they imply current densities of hundreds μA/m2. Occurrence of such “current singularities” is studied. The nature of the events is discussed.